Truck



Oct. 30,1934. H, A, VAN GUELPEN I 1,979,236

TRUCK- Filed Dec. 3, 1930 0 I5 Sheets-Sheet 1 INVENTQR J ATTORNEY Oct. 30, 1934. H. A. VAN GUELPEN 1,979,236

TRUCK Filed Dec. 3, 1930 Sheets Sheet 2 INVENT R ATTORNEY Oct. 30, 1934. A, V GUELPEN 1,979,236

TRUCK De 5, 1930 3 Sheets-Sheet. 3

INVENTOR A TTORNE y Patented Oct. 30, 1934 PATENT OFFICE TRUCK Herman A. Van Guelpen, Cincinnati, Ohio, as-

signor to The Yale & Towne Manufacturing Company, Stamford, Conn.

Application December 3, 1930, Serial No. 499,703

34 Claims.

This invention relates to improvements in lifting trucks. More'particularly, it relates to an improvement in the mounting and control of the handle of the lifting truck; also to the arrangement of detent meansfor maintaining connection between lifting means on the truck steering handle and elevating means mounted on the frame of the truck, whereby the two will remain in cooperating relationship during movement of the ban- .One object of my invention is to. arrange for detent means which cooperate with a lifting hook carried by the handle of the truck, and a second hook member carried by the lifting means of the truck, so as tomaintain the two hook members in engagement during movement of the operating handle.

A further object of the invention is to arrange the'aforementicned detent means so that they will be spring pressed into a position wherein to hold the two hook members in engagement, but will be movable into position to release the two members from engagement when the truck elevating platform is lifted to, a predetermined position.

salt is a further object of the invention to so arrange the spring pressed detent means, that they normally obstruct engagement of the hook member of the handle withthe hook member of the lifting means, so that one of said hook members must move the detentmeans out of obstructin position prior to its engagement with the other hook memberythereafter permitting the detent means to be spring pressed into holding position.

A further object of my invention is to devise a counter balanced operating handle, arranged to prevent the falling of the handle in a downward direction onto the foot of the operator, and to facilitate the upward movement thereof.

Further advantages and beneficial results in operation of my invention will be apparent from the following description of one embodiment of my invention, taken in connection with the accompanying drawings, in which Fig. l is a partial section showing my invention in one of its operating positions. Fig. 2 is a partial view of Fig. 1,

showing portions of the operating mechanism in a second position. Fig. 3 is a view similar to Fig. 1, showing the mechanism in still a further operating position. Fig. 4 is a top view and partial section of my invention. Fig. 5 is a side view and elevation of the spring-pressed detent member.

' Referring now more particularly to the drawings, and especially Figs. 3 and. 4, reference numerals 10 and 11, indicate a pair of side frame members constituting a portion of the frame of a truck. While I show in my drawings, merely the front end of these frame members 10 and 11, it will be readily understood by one skilled in the art, that these frame members are joined at their rear ends and are connected by cross members so as to form the usual type of frame of a truck, as shown in the patents to William Stuebing, Jr., Nos. 1,706,194 and 1,750,289. The front ends of r the frame members 10 and 11 are joined by a saddie member 12, secured to the members 10 and 11 by the bolts 12. This saddle has formed thereon a steering bearing head 13, in which the steering shaft 14 is mounted for movement about a vertical axis. This steering shaft 14 extends downward vertically through the head 13 and is equipped with a pair of yoke members 15, carrying an axle 16, upon which the steering wheels 17 and 18 are mounted.

Secured to the steering shaft 14 is a collar having a pair of cars 19, in which is mounted the pivot shaft 21, carrying the handle assembly 20.

In this construction, the handle 20 will be movable vertically about the pivot shaft 21, and at the same time will be able to move in a horizontal plane about a vertical axis with the steering shaft 14 for the purpose of actuating the steering wheels 17 and 18 of the truck in any particular direction.

An elevating platform comprising side frame members 22 and 23 is supported by link members 24' and 25' relatively to the main frame members 10 and 11, whereby said elevating platform may be moved forward and upwardly relatively to the main frame. These frame members 22 and 23, 0 carry forwardly thereof and uniting the front ends a transverse bar member 24, formed with an extended arcuate flange member 25. This arcuate flange member 25 is adapted to cooperate with a hook member 26 pivotally mounted relatively to the handle assembly 20, as will be presently described. In regard to the mounting of the main frame members, the steering head, the handle 20, and the flange member 25, I have so far described that which was disclosed to the art by Stuebing in his Patent 1,750,289, my invention being especially applicable to his construction, although not limited to use only in combination with his particular arrangement.

Therefore, while for the purposes of illustrating the application of my invention, I shall describe it with reference to trucks of the type disclosed in the above patents, it should be understood that my invention is applicable to other types of trucks which are known in the art, or

which may be hereafter designed to more particularly cooperate with the invention disclosed herein.

The hook member 26, instead of being mounted directly on the handle member 20 in the manner in which it is mounted in the trucks of the prior art, as exemplified by the Patent 1,750,289 referred to above, is mounted on an intermediate link member 2'7 by means of a pivot 28, the intermediate link member being in turn mounted on the handle on the pivot 29. This intermediate link member is equipped with a surface 30 cooperable with a flat lug portion 31 carried by the handle adjacent to its bearing on the pivot 21. The purpose of this construction is to produce an easier lifting truck and to get the greatest amount of power when the load is the greatest, and to better distribute the load lifting effort, all of which will be described presently.

The hook member 26 has an upwardly extending foot-operated pedal 32 whereby it may be moved into cooperation with the arcuate flange member 25. Downward movement of the handle 20 will act to rotate the handle about its pivot 21, and move the truck platform through means of hook 26 and the flange 25 from the position of Fig. 3 to the position of Fig. 1. As will be readily understood, during the first part of the lifting movement, the link 27, carrying hook 26 will vary in its angular relationship to the handle 20 by rotating about the pivot 29, until finally its fiat portion 30will abut the flat portion 31 of the handle, as is shown in Fig. 1, so as to effect a direct and faster lifting action between the hook 26 and the handle 20, as though the hook 26 were pivoted directly on the handle 20. This arrangement is designed to vary the relation between the pulling or lifting force applied to handle 20 and the leverage and speed of movement given to the lifting frame. Thus, the greater leverage is given the handle 20 when it is in its upward and most awkward position, and when the load is greatest. Similarly, the leverage is reduced and the lifting speed is increased at the point where the operator is best able to apply his physical power.

This arrangement of the lifting hook relatively to the lifting handle is in itself not my invention, but is described herein since my invention is applied with relation thereto. For a further description of this compound lift arrangement, I shall refer to the application of William Stuebing, Jr., filed on November 8, 1929, and bearing the Serial Number 405,580, in which the compound handle lift is more fully described and claimed.

I shall now describe my invention as it may be appliedto a truck embodying the constructions and inventions already. indicated above. The transverse bar member 24 connecting the side frame members 22 and 23 of the elevating frame is equipped with downwardly and forwardly extending lugs 34, each carrying a pivot shaft 35, and upon these pivot shafts I mount a detent member 36, shown more especially in Fig. 5. This detent member 36 has a rearwardly extending shoulder member 3'7, which is connected by a spring 38 to the flange member 25, so as to maintain this detent member spring pressed into the position of Fig. 3 during the normal operation of the truck, this shoulder 37 being adapted also to limit this spring-pressed movement of the detent.

Mounted at one'end of the detent member is a foot-operated pedal 39 whereby this detent member 36 may be depressed at any time. This pedal member 39 has a surface camming portion 40, which cooperates with means carried on the frame of the truck for a purpose to be described hereinafter.

The elevating frame member 23 carries thereon a stud 41, upon which is mounted a roller 42, which cooperates with a treadle hook 43 for holding the elevating platform in elevated position once it is raised by the action of the hook 26 and the arcuate flange member 25. This treadle hook is equipped with a camming surface 44, which cooperates with the surface 40 of the detent'member 36 for a purpose to be described hereinafter.

When it is desired to lift the truck, by operating the arcuate member 25-by the hook member 26 through means of a handle 20, the handle 20 is first placed in its upright position shown in Fig. 3. It will be quite obvious that the hook member 26 may now be engaged with the arcuate member 25 at various angular steering positions relatively to the member 25, so that a side lift action may be obtained. As is also readily seen from Fig. 3, the detent member 36 is normally maintained in an obstructing position to prevent engagement of the hook member 26 and the arcuate flange member 25. The operator will next step on the pedal 32, and will, by means of that pedal. operate the hook member 26, so as to move the detent member 36 against the pressure of its spring 38, and permit the hook member 26 to en'- gage the flange 25 in the manner indicated in Fig. 2. He will then move the handle 20 in a downward dirction, so as to lift the elevating frame to the position of Fig. l as is readily understood.

During this lifting operation, it will be clear that the detent member 36 has been operative to maintain the hook member 26 in continuous engagement with the flange member 25. In the normal operation of the flange 25 and the hook member 26, these members would be maintained in engaging position by the tension between the same, but any backward movement or any accidental relieving of the tension would separate these two members. It is obvious that the detent member 36 will operate to prevent any accidental separation of these two members and will thus prevent accidental falling of the handle 20 or the application of force thereto without the existence of engaging movement between the flange 25 and the hook 26, with resultant injury to the operator.

When the elevating frame has been raised to the position of Fig. 1, it will be readily seen the treadle hook 43 will ride over the roller latch 42' and will engage in the same to maintain the elevating platform in its elevated position. At the same time, the surface 44 of the treadle hook will engage the surface 40 of the detent member 36 and will urge the same to: the rearward position illustrated in Fig. 1, thus permitting the hook 26 to drop by gravity from the position of Fig. 1

slgeraaae rbytmovement of athe' truck lifting platform a to z a :pre4determinedrliftedlposition.

I Inthandling -zand imaneuvering zza struck, -the lhamlle ':or operating; lever, aastthe Lease tmay Ibe,

1 r5 not only becomes heavwand tiresomewto the-oplnsad ditinnctoitheiaction :of-the sprlng'52.

.eratorjsbut itcis oftentthercause of accidental-1 and sse'riouszinzinryyshould it fall andstrike the operiaton z'espeoially: his: foot. 2 Ishavez provided a very SSTmpIeHatta'c'hinent' for preventing this: dropping movementtofitheihandle; and fon'counterbalanc- Ling thetsamer in its: movement: in either aidown- Ward onmipwardidirectien. :For this purposenfexiteridetheieartmembersr L9 to form apair ofi lugs'45, Lime/niches mounted a; pivot shaft 46. Supported on this shaft is an upwardly-extending rod llsecured'iby ai piv t=48f t0= a'rsliding sleevelike member e49, mounted: torsli'dingr movement on the handle extension 50. The:sleevelike member 49: has an iear-amember'rtil whicir is connected by a spring- 52 zm avlugtoe on the'lowerz portion of: the handle asisembiyiflfl. It will 'be reaidi'ly understoodithat: the mwnward movement of 1 the handle '20 1 from: the @position ef 'T'Eig. :3 :wi-llwact a to extend the rode? findi-thetsleevelikeianemberree in thesmanner of a .tagglesaigainst therpressure of the spri-ng :52. As thel'haiddlexmovesrmom and more to the position Zofflillg. 31, .this :extension zloecomesconsiderable, land eincreases the ::spring :acti-on resisting 'the Jdownward 'imovement of the handle. :-Fru-thermore, 1thefangularitywfl the rod- :47 :relatively to therssleevelikermember 49, causes: a distinct" frictional pressure ".of the --'sleevelike member 49 iagarlnst l the :handle extension '50 during this fiiownwardrmovernent, .thisa frictional check being y thisrra-ther unique arrangement, .I' obtain a bali ancedthandleiactienr.ofi,:great= efficiency and commarativessimplicity.

' While iIffhtl e described my l invention was 'a-pplied td atparticula'n type oftnuck, in cooperation with particular features disclosed-tin certa'in; patr ents andlfa fpendingxapplicationa it willi be readily understood byirone skilled: in the art, that myiintvention iis :applicable J to "many :forms it of truck r-ienstruetion, rand ithat "variations-10f the same Within 1 the sscope :of r the appended "claims :may

, readilyrocountoz one skilled in the art.

l I elaima- 1.- ilittlng'itrucki comprising in-rcombinatlon,

fialmai'n 'frainm an elevating frame mounted .onthe 'main frame and movable upwardly relatively -theretog' an operating member operatively assoelated with saidlelevating framava swingingilever carried by sai'd main frameginter engagi-ng :means oarried by said leverxan'd isaid operating nierfiber wliereby movement 16f said :lever acts to raise=sai'cl' elevating frame relatively: to sai'dfmain :trarne, and a spring actuated detent adapted-to press "against said engaging means to maintain sai'dinter engaging means inengagement.

1*A liftingtru'ck comprising, in combination, arnflain frame, anelevating frame mounted on the 'main frame'xandmovableupwardly relatively", thereto, an I operatingmember 'operatively as- :sociated with said elevating frame, a swinging 'lever'carried by said' main frame, inter-engaging means carriedby said lever and said operating member whereby movement or said lever. acts to iraise said elevating frame relatively 'to said main frame, said inter en'gaging means being normallydisengaged and adaptedto be engaged upon manipulation and arranged so that when engaged the liftingten'sion tends to maintainthe same in engagement, an'd additionalmeans tendring" independentlylto press saidrmeans .intoe'en- .tga'gement.

13..1A:.:liftingttnuck: comprising, i in :combination, azmaimframe, Han elevating 1 frame mounted on stnetmaiinz'rrame and movable upnnrdlyrrelative'ly ".8

randemeans en said relevatingi frame adapted (to 35 presssaid means into engagementnnea they have become engaged.

=4. n i lifting truok comprising, in "combination,

a main heme, -=an 'elevatin=g f frame mountedi on the main frame and movable upwardly: relative- 1 1y thereto, a= swinging lever carried by said main f frame *and" normally having i freeunencumbered "movement;inter engaging means normally'mainta-me d separated and adapted to be engaged by predetermined eparation, sai'd means connetti-ng "said lever an'dsaid elevating'fra me whereby movement of said lever 1 acts to raise =said elevating "frame relatively to-said main frarne, said interengaging means being-arranged so that the lifting tension tends to maintain thesameiin -engagement,--and=a'dditional' means tending independently to-presssaid means into engagement.

'5. A lifting truck comprising,' in combination, a mainframe, an elevating frame mounted 'on" the frame and movable upwardly relatively thereto, a swinging lever carried 'by'said main frame, inter-engaging means normally =rnaintained separated and adapted to be-engagedby predetermined operation, saidmeansmonnectin'g said lever and said elevating frame whereby no movement of said lever'acts toraise said elevating "frame relatively 'to said main frame, said inter-engaging means being arrangedso' that the liftingitension tends to maintain the same in ena'gement, and spring "actuated means "tending independently to' urge and press said means into engagement.

"6. A lifting truckcomprising, in combination, amainframe, an elevatingframe'mountedon the main ."frame and =movable upwardly "relatively thereto,'a"swinginglever carried by said main frame, inter-engaging means normally main- 'tained'separated and adapted to be engaged by predetermined operation, said" means "connecting said 'lever and said "elevating frame whereby movement of said lever acts to raise said'elevat- 'ing frame relatively to ."said main frame, 'said inter-engaging means being arran ed so that the lifting tension. tends to maintain the same in en- .ga ement and spring actuated meansicarried' by .said elevatingframe and adapted to'urge and press said means into engagement.

"7. Aliftin'g truck comprising, in combination, a mainframe; an elevatin frame'mounted on the .main frame and movable upwardly relatively thereto, a swinging lever carried by'said main frame, inter-engaging means carried by" said lever and said elevating 'frame whereby movement .ofisaidleveraaets to raise said elevatingframe relatively to .-said' main frame, said inter-engag- .ingimeans being arranged so that the lifting tension tends to. maintain the same in engagement, and a spring actuated detent carried by said elevating frameand tendingto, press the Ilever means in engagement with the means on the elevatingfframe.

[8, A; lifting l truck comprising, in combination, Lamainframe, an elevatingfframe mounted on the main -.'frame and .movable upwardly relatively thereto, a swinging lever carried by said imain press frame, means normally maintained separated and carried by said lever and said elevating frame and. adapted to be inter-engaged whereby movement of said lever acts to raise said elevating frame relatively to said main frame, said inter-engaging means being arranged so that the lifting tension tends to maintain the same in engagement, and additional means independent of the lever and its mounting adapted to press said inter-engaging means into engagement after they have been engaged.

9. A lifting truck comprising, in combination, a main frame, an elevating frame mounted on the main frame and movable upwardly relatively thereto, a swinging lever carried by said main frame and normally free of any contact with said elevating frame, engageable and disengageable means of connection between said elevating frame and said lever comprising inter-engaging hook members, said hook members being arranged so that the lifting tension maintains the same in engagement, and additional means tending independently to press said hook members into engagement.

10. A lifting truck comprising, in combination, a main frame, an elevating frame mounted on the main frame and movable upwardly relatively thereto, a swinging lever carried by said main frame and normally free from any connection with said elevating frame, engageable and disengageable means of connection between said elevating frame and said lever comprising interengaging hook members, said hook members being arranged so that the lifting tension maintains the same in engagement, and a spring actuated means adapted to press one of said hook members into engagement with the other of said hook members.

11. A lifting truck comprising, in combination, amain frame, an elevating frame mounted on the main frame and movable upwardly relatively thereto, a swinging lever carried by said main frame, means of connection between said elevating frame and said lever comprising inter-engaging hook mcmbers,sai.d hook members being arranged so that the lifting tension maintains the same in engagement, and a spring actuated detent carried by said elevating frame and acting to maintain said hook members in yieldable engagement.

12. A lifting truck comprising, in combination,

a main frame, an elevating frame mounted on the main frame and movable upwardly relatively thereto, aswinging levermounted on said main frame, inter-engaging means on said lever and elevating frame normally maintained disengaged but engageable upon predetermined operation, and means additional to said inter-engaging means and said lever, and mounted so as to cooperate with said engaging means to urge and the same into engagement.

13. A lifting truck comprising, in combination, a main frame, an elevating frame mounted on the main frame and movable upwardly relatively thereto, a swinging lever carried by said main frame, inter-engaging means carried by said lever and elevating frame, and adapted to be engaged and disengaged at will, and means on said elevating frame adapted to press said means into engagement after they have been engaged. a

14. A lifting truck comprising, in combination, a main frame, an elevating frame mounted on the main frame and movable upwardly relatively thereto, a swinging lever carried by said main frame, a connection between said lever and said elevating frame comprising inter-engaging hook members, and a spring actuated detent carried by said elevating frame and adapted to press said hook means into engagement.

lever and engageable with the arcuate hook mem- I ber, and a spring actuated detent adapted to maintain said lever hook member in engagement with said arcuate member.

16. A lifting truck comprising, in combination, a main frame, an elevating frame mounted on the main frame and movable upwardly relatively thereto, a vertically swinging truck'manipulating lever, an arcuate hook member secured to the elevating frame, a hook member pivoted to the lever and engageable with the arcuate hook member in various angular positions relatively thereto, and'a detent cooperable with said hook and arouate member to maintain the same in engagement.

17. A lifting truck comprising, in combination,

a lower frame, an elevating frame, a depending arcuate flange on said elevating frame, a steering shaft rotatably mounted on said lower frame, a handle pivotally mounted on said steering shaft, a lifting hook pivotally mounted on said handle and extending rearwardly beneath said arcuate flange when said handle is in either its normal central position or to either side thereof,said hook being unbalanced so that it remains normally out of engagement with said flange but may be caused to engage the same, and a spring actuated detent adapted to maintain said hook member in engagement with said arcuate flange after said hook member has been moved into engagement with the flange.

18. A lifting truck comprising, in combination, a lower frame, an elevating frame, an arcuate flange on said elevating frame, a steering shaft rotatably mounted on said lower frame, a handle pivotally mounted on said steering shaft, a lifting hook pivotally mounted on said handle and adapted to engage said arcuate flange, said hook'being normally maintained out of engagement with said flange but being movable into engagement with the same, and a spring actuated detent adapted to maintain said hook memberin engagement with said flange once said'hook has been moved into engagement with the same.

19. A lifting truck comprising, in combination, a lower frame, an elevating frame, a hook member on said elevating frame, a steering shaft rotatably mounted on said lower frame, a handle pivotally mounted on said steering shaft, a second hook member mounted on said handle and adapted to engage said first hook member, said hook members being normally maintained out of engagement with one another during the ordinary operation of the steering handle, but being arranged for movement into engagement with one another, and a spring pressed detent member positioned so as to press said hook members into engagement once they are engaged.

. 20. A lifting truck comprising, in combination, a lower frame, an elevating frame, a depending arcuate flange on said elevating frame, a steering shaft rotatably mounted on said lower frame, a handle pivotally mounted on said steering shaft, a lifting hook pivotally mounted on said handle and extending rearwardly beneath said'arcuate flange-when said i handle iszin either: itsrnormal central; position= or: tom eitherside: thereof; said hook beingi unbalanced 1 so that: it: remains nor 1 mallyrout of engagement. with=said flange-but -=may be caused to engagethesame, and-a spring:

actuatedfdetent adaptedto obstruct movement of a said I hook into engagement: with said flange andto .be movable yieldably-out of obstructing positionibyssaidlhook, said detent being then movable, into:v position ;tomaintain said I hook. in

engagementmith .said flange.

21. .A lifting.- truckcomprising, in combination, anlower: frame, an elevating frame anarcuate.

flange: on "said elevating frame, a-steering shaft rotatably mountedton said "lower frame, a handle. pivotallymounted on said-steering shaft, a lifting hook pivotally: mounted .on saidlhandle and adapted ftozengagesaid :arcuate: flange, said hook member.' being; normallyumaintained' out of engagement with said flange but beingmovable into engagement'with the same, and a spring actuated detent adapted .to obstruct movementof said hook into engagementwith said'fiange: and .to be movable-.zyieldably. outiof obstructing position by y saidihook, saiddetent .being. thenmovable into position to maintainsaid hook in engagement with said flange;

.22. .A'lifting truck comprising, in combination, aalower'frame, an elevating. frame, a hook memher: on said. elevating. frame, a steering shaft rotatably mounted on said lower'frame, a handle pivotallymounted .on'said steering shaft, a second h'ook member: mounted on said handle and adaptedtoc-engage. saidfirst hook member, said ,f'hOOk. members: being. normally maintained out of engagement during the ordinary operation of the steering handle, but being movable into engagement with one another, and a spring actuated detent adapted to obstruct movement of said hook ,imembers into inter-engaging position and to be movable yieldably out of obstructing position during inter-engaging movement of saidhook members, said detent being then movable into position to maintain the hook members in engage- "ment.

tends to maintain the same in engagement, additional means tending independently to press said means into engagement, and means on said truck adapted to throw said additional means into releasing position when said elevating frame has been lifted to a predetermined position.

24. A lifting truck comprising, in combination, a main frame, an. elevating frame mounted on the main frame and movable upwardly relatively thereto, a swinging lever carried by said main -frame, inter-engaging means connecting said i tension tends to maintain the same in engagement, additional means tending independently to maintain said means in engagement, and means on said truck adapted to lock said elevating frame in elevated position, said means being operable to render said additional means inoperatiye to. .maintain said: inter engaging. means: in position: when. said elevating framehasbeem raised 1 a predetermined amount.

25.: A lifting truck comprising, in combination; amainframe, an elevating frame mountedzon; 80 the main frame and movable upwardly relatively; thereto, a swinginglever carriedby-said main:r frame; inter-engaging:- means. connecting. said; lever and.said.elevating frame-whereby move ment of; said lever acts to raisesaid elevating: 85. frame relatively to said mainframe, saidintere' engaging means being arranged sothat the fifteing tension tendsv tomaintainthe same; in err-.- gagement, a. spring. actuated detent .carriediby said elevating. frame'and tending. to.press.1the 9ft inter-engaging. means into; engagement; and: means on saidtruck: adapted, .to throw saidLdee tentinto releasing position when said elevating: frame has been moved upwardly a predetermined; amountl 26.. Alifting truck comprising, in combination,. a main frame, an elevating frame mountedaon the main frame and movable upwardly relatively thereto, a swinginglever carried by said frame, inter-engaging means carried by saidsZBdl.

lever and said elevating frame whereby move mentof said lever acts to raise said elevating frame relatively to said main frame, said inter engaging means being arranged so thatthe lifting tension tends to maintain the same inengagea 135: ment, a spring actuated detent carried by said elevating frame and-tending to press the lever means into engagement with: the means on-the elevating frame, and means on said truck adapt-- ed to lock said elevating frame inelevated 'posi' 111) tion, said means being operable to render said detent inoperative to maintain said lever and frame means in engagement.

27. A lifting truck comprising, in combination, a main frame, an elevating frame mounted on 115, the main frame and movable upwardly relatively thereto, a swinging lever carried by said main frame, means of connection between said elevating frame and said lever comprising inter-engaging hook members, detent means, means whereby 12c said detent means tend to press said hook members into engagement, and means on said truck adapted to render said detent means inoperative when said elevating frame has been lifted a predetermined amount.

28. A lifting truck comprising, in combination, a main frame, an elevating frame mounted on the main frame and movable upwardly relatively thereto, a swinging lever carried by said main frame, means of connection between said elevat- 13o ing frame and said lever comprising inter-engaging hook members, a spring actuated detent carried by said elevating frame and acting to maintain said hook members in yieldable engagement, and means on said truck adapted to lock said elevating frame in elevated position, said means being operable to render said detent inoperative when said elevating frame has been moved to its elevated position.

29. A lifting truck comprising, in combination, a main frame, an elevating frame mounted on the main frame and movable upwardly relatively thereto, a swinging lever, inter-engaging means associated with said lever and elevating frame whereby said frame may be elevated, means addi- 145 tional to said inter-engaging means and said lever and mounted so as to press said means into engagement, and means on said truck adapted to render said means inoperative when said elevating frame has been lifted a predetermined extent.

Q 30. In a truck, a manipulating lever pivotally mounted on said lifting truck, a lifting platform for movement in a vertical plane, means carried by said lever whereby vertical movement thereof acts to lift said platform, a friction element slidably mounted on said lever, a toggle rod secured to said element and relatively to said truck for moving said element outwardly on said lever as said lever moves from a vertical position to a horizontal position, said toggle rod being angularly arranged relatively to said element so as to press the same with increasing force against said lever as said lever moves to its horizontal position.

31. In a truck, a manipulating lever pivotally mounted on said lifting truck, a lifting platform for movement in a vertical plane, means carried by said lever whereby vertical movement thereof acts to lift said platform, a friction element slidably mounted on said lever,.a toggle rod secured to said element and relatively to said truck for moving said element outwardly on said lever as said lever moves from a vertical position to a horizontal position, said toggle rod being angularly arranged relatively to said friction element so as to press, the same with increasing force against said lever as the lever moves to its horizontal position, and a spring secured to said element and to said lever and adapted to resist outward movement of the element on said lever so as "to maintain said lever in its vertical position.

32. A lifting truck comprising, in combination,

fa main frame, an elevating frame mounted'on the main frame and movable upwardly relatively thereto, a swinginglever pivotally mounted, on said main frame and having means for operating said elevating frame, a sliding sleeve on said lever in frictional contact therewith, and a toggle rod secured to said sleeve and to said frame, and adapted to slide said sleeve on said lever as said lever is moved about its pivot.

33. A lifting truck comprising, in combination, a main frame, an elevating frame mounted on the main frame and movable upwardly relatively thereto, a swinging lever pivotally mounted on said main frame and having means for operating said elevating frame, a sliding sleeve on said lever in frictional contact therewith, a toggle rod secured to said sleeve and to a portion of the frame, anda spring secured at one end to said sleeve and at the other end to said lever and adapted to press said sleeve toward the pivoted end of said lever, said sleeve being slidable relatively to said lever against the pressure of the spring when actuated by the toggle rod upon movement of the lever about its pivot.

34. A lifting truck comprising, in combination, a main frame, an elevating frame mounted on the main frame and movable upwardly relatively thereto, an operating member operatively associated with said elevating frame, a swinging lever carried by said main frame, said lever and said operating member being normally out of engagement to allow free movement of said lever, but having means movable into engagement whereby movement of said lever acts to raise said elevating frame relatively to said main frame, and additional means mounted and movable independently of said engaging means and adapted to press and urge the same into engagement.

HERMAN A. VAN GUELPEN. 

